This invention relates generally to automatic sorting of articles of mail, and more particularly, to a method and apparatus for facilitating the automatic sorting of mail by optical scanning equipment.
The sorting and processing of mail by most postal services today still involve a number of manual operations. Accordingly, mail frequently moves slowly, and postal services often incur large deficits due to their high labor costs. In order to keep postal rates from escalating to prohibitive levels, improved methods for mail handling must be found.
Sorting of letters by electronic scanning of zip code numbers is being done by the U.S. Postal Service, but only to a limited extent. This system, known as Optical Character Recognition (OCR) provides for numerals imprinted on the face of envelopes to be scanned electronically, converting the shape of each character into digital data to be used for sorting and other processing purposes. It requires that letters to be processed in this manner have machine or typewritten addresses and otherwise conform to rigid specifications.
Other known coding and sorting methods which could possibly be adapted to use in the automated processing of mail include:
(1) The punching of postal cards and envelopes with zip code hole patterns in a manner corresponding to that used in the preparation of standard tabulating cards. Mail could then be sorted through use of pins, electrically charged brushes or light beams which penetrate through and sense hole patterns.
(2) The imprinting or marking on the white surface of envelopes or cards a pattern of black bars which would represent the address code. Through use of electronic scanners in which photoelectric cells are actuated by variances in reflected light, the automated sorting of mail could be accomplished.
(3) The placing with a graphite pencil of a mark in selected oblong circles preprinted on the face of a card or envelope. This system, known as mark sensing, would permit mail to be electronically sensed.
The foregoing methods require either unobstructed holes in the article through which various sensing means can extend, or imprinted characters, bars or manually entered marks precisely formed and positioned on the face of the article to enable electronic scanning. As will become increasingly evident, these methods of encoding and sensing are fundamentally different from those proposed under the present invention.
It will be appreciated that wider use of automatic sorting equipment to replace those operations presently being performed by the postal services, either partially or entirely by hand, would result in significantly lower costs and more rapid and reliable mail delivery. Accordingly, there exists a need for an effective, economical and uniform method and apparatus for automatically sorting mail. As will become apparent from the following, the present invention satisfies that need.